Colonizing the moon once must have seemed a good idea, but as this quietly dour graphic novel opens, the last settlers are packing up and returning to Earth. Among the few remaining inhabitants is the titular mooncop, whose duties now consist of such mundane tasks as searching for a lost (spacesuit-clad) dog or retrieving a Neil Armstrong automaton that wandered off from the Museum of the Moon. Lonely and bored, he submits a transfer request that’s denied. Suspecting depression, however, area command sends him a defective therapy unit that promptly breaks down. As lunar population dwindles to almost nothing, the cosmic constable discovers an unexpected reason to stay put. Gauld, who draws a weekly strip for Britain’s Guardian, uses a boldly minimalist style—the characters are just one stage beyond stick figures—that’s augmented by deftly placed crosshatching and the use of a single cobalt tone as the only color, making the landscape truly a blue moon. A drolly melancholic tale that’s more an exploration of inner than of outer space.